Peptide analogues stimulating hormone melanocytes alpha

A substantially pure compound that selectively binds melanocortin receptor 1 (MC1R), said compound comprising: a) a nuclear tetrapeptide having the sequence: His Xaa1 Arg Trp (SEQ ID NO: 1) or D-Trp D-Arg Xaa2 D -His (SEQ ID NO 2), wherein Xaa1 is D-Cha, D-Phe or Cha, and Xaa2 is D-Cha, D-Phe or Phe; b) a C-terminal polypeptide having the sequence: D-Ser D-Ile D-Ile D-Ser D-Ser (SEQ ID NO 3); or a pharmaceutically acceptable salt thereof.